WASHINGTON - Government officials were trying Friday to trace a cow shipped to the United States from the same Canadian herd as an animal infected with mad cow disease, but officials said it was unlikely the imported cow was infected.

Canada announced a case of mad cow disease Sunday, only days after the Bush administration said it would lift a U.S. ban on Canadian cattle.

The infected dairy cow was 8 years old and from Alberta. It was born in the same herd, within one year, of a cow shipped to the United States in February 2002 for immediate slaughter, the Agriculture Department said.

In Canada, investigators identified 93 dairy and 48 beef animals that were born in the year before through the year after the infected cow was delivered in October 1996. Investigators are trying to trace all 141 animals, including the one shipped to the United States.

Related Stories

Nonetheless, DeHaven said, the department is making "every reasonable effort to obtain and provide information about the disposition of this animal as well as any other birth cohorts that are traced to the United States through Canada's epidemiological investigation."

In May 2003, when the first Canadian cow tested positive for mad cow disease, officials traced a small number of animals from the same herd to the United States.

American cattle producers said the government's announcement confirms their belief that Canadian cattle imports should not resume as scheduled on March 7. "It further demonstrates that USDA is dangerously premature in issuing this final rule," said Bill Bullard, CEO of R-CALF United Stockgrowers of America.

Sen. Kent Conrad, D-N.D., questioned whether Canada is enforcing a ban on use of cattle remains in cattle feed.

Mad cow is the common name for bovine spongiform encephalopathy, or BSE. People who eat tainted meat can contract a brain disease called variant Creutzfeldt-Jakob disease.